U.S. Pat. No. 2,988,835 of Francis S. Murphy discloses a process for producing a lightweight flat character for a display sign. In the process described in this patent, a laminated panel material 10 comprising a styrene type plastic foam core 16 which is heat sealed to sheets of kraft paper 17 is die cut. The laminated character thus produced is taught to be useful for display signs. However, if one were to attempt to make a sign from the laminated character by pushing it partially or completely into the foam core from which it was cut, the kraft paper wrinkles and thus presents a poor image.
The Murphy patent does not specify the thickness of its laminated panel material 10, merely stating that it is ". . . of uniform thickness . . . . " However, it is apparent to those skilled in the art from the disclosure of the Murphy patent and its drawings that such laminated panel material 10 has a thickness of from about 0.06 to about 2 inches. A laminated character cut from such a panel material does not present a sufficiently definite three-dimensional appearance.
The foam characters produced by the process of the Murphy patent could not be used to produce signs with attractive three-dimensional effects. For many years, such signs have been produced by using "gatorboard," which is a styrene foam sheet laminated with white, tan, or black kraft process cellulose paper and which is manufactured by the International Paper Company of 6400 Poplar Avenue, Memphis, Tenn. This "gatorboard" is rather expensive, generally costing about 120 dollars for a 1.5 inch thick 4'.times.8' sheet.
When characters are cut out of such "gatorboard," and then reinserted into the area from which they have been cut, there generally is a gap of at least about 0.12 inches between the characters and the base material. Thus, these characters cannot be friction fit within the recesses produced in the base material. To produce a sign from such "gatorboard" in which the characters can be friction fit, one must separately machine recesses within another piece of "gatorboard" which will match the dimensions of the characters machined from the first piece of "gatorboard." This is a prohibitively expensive process.
One may use a laminated foam panel instead of the "gatorboard" to attempt to produce such three-dimensional signage with friction fit characters. However, when the characters are die cut by conventional means from such panel, a substantial amount of the material is fractured and thus presents a poor appearance as well as poor structural integrity.
It is an object of this invention to provide a sign structure which presents an attractive three-dimensional affect and which has a multiplicity of laminated characters attached to and disposed within a laminated base.
It is another object of this invention to provide a sign structure which affords a cost effective means for providing a wide range of graphic effects on various surfaces.
It is yet another object of this invention to provide a lightweight, substantially damage-resistant sign structure.